The most common use for electrical conduit connectors is to facilitate the connection of a conduit or cable to a junction box. The junction box can be a variety of electrical enclosures such as an outlet box, transformer enclosure, circuit panel, lighting fixture, etc. Similarly, the conduit can be rigid or flexible, or could be hose, other tubing capable of routing electrical wire or cable (e.g., fiber optic cable). Cable can be non-metallic sheathed cable, portable cord, or a variety of other types of electrical conductors. The instant application is equally successful in connecting a plurality of types of conduits, cables, and other electrical conductors to a wide variety of boxes and other enclosures. Therefore, as used in this specification, unless specifically stated otherwise, the term conduit is not limited to standard rigid electrical conduit, but shall be intended to mean any type of: conduit, cable, cord, or any other type of electrical conductor.
Many commercial and residential buildings have electrical installations with many types of conduit-to-junction box connections that utilize electrical connectors. The two most common types of electrical connectors are a snap-in connector and a multipart connector which can be composed of two or more components that utilize a threaded male end in conjunction with a threaded female locknut, hereinafter referred to collectively as a two-part locknut connector. In the case of the two-part locknut connector, the male threaded end is inserted into the junction box through a knockout (e.g., a hole or other opening). A rigid connection is established by threading the locknut onto the male end in the junction box interior. The snap-in connector is another commonly used connector, which utilizes a snap ring to quickly connect the connector to the junction box. Either type of connector is integrated with an adapter end, which allows the attachment of conduit, cable, or a variety of types of hollow tubing.
The installation of electrical systems is generally expensive as an electrician must first install the enclosures, route conduit between each enclosure, install connectors and then pull all necessary electrical wiring through the conduit. In other words, installation is expensive because it is labor intensive. The commercially available electrical connectors are one factor accentuating the labor intensiveness. Locknut connectors increase the cost of installing electrical systems for a number of reasons. The current art for two-part locknut connectors are plagued with labor intensive problems. First, the locknut connectors are shipped from the manufacturer preassembled. That is, the electrician must first remove the locknut from the male end before it can be installed. Once the male end of the connector is placed through the knockout, the electrician must rethread the locknut onto the connector from the interior of the junction box.
Two hands are required to disassemble and then reassemble the connectors in the knockout. Consequently, it is difficult to hold a tool or a piece of conduit while reassembling the connector. Once the locknut is threaded it must be tightened. In accordance with many building codes and safety regulations, connectors must be firmly and reliably attached to junction boxes. To properly tighten the two-part locknut connector, the electrician must use a tool, usually a set of pliers or a screwdriver. Occasionally, when the proper tool is unavailable, an electrician will use any object within reach. These situations, while rare, raise serious safety issues. In many instances, however, to “get the job done” the locknut is “finger” tightened. Those persons skilled in the art know that finger tightened two-part locknut connectors can eventually loosen, and a loose connector can cause great strain to be put onto the electrical wires and their connections resulting in an increase in the probability of, for example, disconnection of the wiring or poor grounding.
Secondly, when the electrician disassembles the fitting by taking the locknut off the connector, the locknut can be dropped or misplaced. This can occur when the electrician is in an elevated position, such as, on a scissor lift or on scaffolding because the electrical conduit is often installed in out-of-the-way places like in rafters and above ceilings. If the locknut cannot be found, the connector is useless. If the electrician decides to retrieve the dropped locknut, the installation time is prolonged.
The snap-in connector presents similar problems. However, the most significant problem is that these connectors, in most cases, do not create a rigid connection. Because the snap ring is sized to accept a variety of box wall thickness, it does not rigidly attach to many boxes. The loose fit may cause, for example, electrical continuity problems.
There remains a need to provide a generally universal connector that is easy to use; e.g., which can be installed quickly and easily without tools, does not require access to the interior of the junction box, and/or can be easily removed and reused in the box; and/or attains a firm connection to the box.